Currently, liquid crystal display (LCD) devices have become a hot spot in the development of displays due to their high-resolution, very wide color gamut and ultrathin size. LCD devices, however, still need to be improved, for example, to rectify the problem of dynamic picture ghosting resulting from the slow response speed of liquid crystal.
Many solutions aim to solve the problem of dynamic picture ghosting in liquid crystal displays, such as black frame insertion, frequency multiplication, flashing backlight, scanning backlight, etc. Among them, scanning backlight is considered to be the most effective method to improve the problem of dynamic image ghosting. In an existing scanning type backlight module, as shown in FIG. 1, several lamps 102 are mounted on the lateral side of the light guide plate 101 and the liquid crystal display is scanned from top to the bottom with a signal. When a pixel unit corresponding to a lamp is being scanned by the signal, the corresponding lamp is turned on and then turned off after the scanning of the signal.
In the existing scanning type backlight module, diffusion (as indicated with the dashed lines in FIG. 1) occurs when light emitted from the lamp propagates in the light guide plate. A region illuminated by a lamp cannot correspond to the pixel units in one entire row of the liquid crystal display—more than a part of the pixel units in one row of the liquid crystal display are illuminated. Thus, progressive scanning cannot be performed for each row of pixel units in the liquid crystal display, affecting the display quality of the liquid crystal display. Moreover, the existing scanning backlight module needs a large number of lamps mounted on the lateral side of the light guide plate. For large size liquid crystal displays especially, this limitation results in a waste of resources and a relatively large production cost.
Accordingly, it is necessary for those skilled in the art to solve the problem of how to design progressive scanning for each row of pixel units in the liquid crystal display with a scanning type backlight module, while reducing the number of light sources and decreasing the production cost.